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1
Essebbahi, Issam, Chadia Ouazzani, Abdallah Moustaghfir, Abdallah Dami, and Lhoussine Balouch. "Analyses physicochimiques de différents thés commerciaux et risque de l’excès de fluor chez la population au Maroc." International Journal of Biological and Chemical Sciences 14, no. 4 (August 17, 2020): 1203–13. http://dx.doi.org/10.4314/ijbcs.v14i4.4.
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Sous la forme de fluorure, le fluor entre dans la constitution des tissus durs comme les dents, les os et les cartilages. L’apport excessif en fluor pendant plusieurs mois ou plusieurs années lors de la période de formation des dents peut provoquer la fluorose. Certains aliments habituellement consommés au Maroc sont riches en fluor. Les traitements industriels de transformation, préparation et conservation mettent à la disposition du consommateur des aliments de coût moins chers et de compositions variables qui peuvent être nuisibles à la santé buccale. L’étude des qualités physicochimiques de différentes sources alimentaires de fluor constituées de différents thés noirs, verts, d’eaux de puits consommés par la population marocaine permet de dévoiler la corrélation entre la consommation des aliments riches en fluor et l’apparition de la fluorose dentaire. Différentes de tisanes de granules de 12 thés verts et noirs ont été préparés selon la variation de la durée d’infusion et du mode d’ébullition. Les teneurs de fluor, calcium, chlorures ont été déterminées par les méthodes spectrophotométriques sur 17 échantillons de thés verts et noirs commercialisés, thés glacés, thés de distributeur automatique, thé de buvette, thé de préparation familiale. La teneur en fluor a été déterminée sur 3 échantillons des eaux de puits, 3 eaux d’assainissement urbain de la région de Skhirat Témara afin de déterminer l’apport de fluor contenu dans l’eau de préparation des tisanes. Les analyses physicochimiques révèlent des taux de calcium de 14 à 60 mg/l, chlorures (14 à 75 mg/l) et de fluor (0,93 à 2,7 mg/l) chez les différents thés verts et noirs étudiés, thé de distributeur automatique, thé de buvette et familiale. Les analyses des taux de fluor de 3 échantillons de thés verts marquent Sultan, Menara, Dahmis et un thé noir Earl Grey révèlent des valeurs supérieures aux normes recommandées pour les enfants et les adultes. Le taux de fluor du thé de la buvette est supérieur à celui du thé de distributeur automatique et de préparation familiale. Ces résultats permettent de prévenir la population face au risque d’atteinte de la fluorose dentaire, en limitant la quantité de fluor ingérée par les aliments consommés. Les analyses des niveaux de fluor de tous les types de produits de thés et des eaux de préparation des thés permettront de disposer de mesures de protection de consommation excessive de fluor.Mots clés : Fluor, aliments, thés, Maroc, excès, risques, fluorose
English Title: Physicochemical analyzes of different commercial teas and risk of excess fluorine in the population in Morocco
In the form of fluoride, fluorine enters into the constitution of hard tissues such as teeth, bones and cartilage. Excessive intake of fluoride for several months or years during the period of tooth formation can cause fluorosis. Some foods usually consumed in Morocco are rich in fluorine. The industrial treatments of preparation, transformations make available to the consumer cheaper foods of variable composition which can be harmful to oral health. The study of physicochemical qualities of different food sources of fluorine consisting of different black teas, green teas and well water consumed by the population reveals a correlation between the consumption of foods rich in fluorine and the appearance of dental fluorosis. Different preparations of herbal teas from granules of 12 green and black teas were prepared according the variation of the infusion time, the boiling mode. The contents of fluorine, calcium, chlorides were determined by spectrophotometric methods on 17 samples of green and black teas from vending machines, refreshment tea, family preparation tea. The fluorine content was determined on 3 samples of well water, 3 urban sanitation water from the Skhirat Temara region in order to determine the fluorine content contained in the water for preparing herbal teas. The physicochemical analyzes reveal levels of Calcium (14 to 60 mg/l), Chlorides (14 to 75 mg/l) and fluorine (0.93 to 2.7 mg/l) in the various green and black teas studied, tea vending machine, refreshment and family tea. The analyzes of the fluoride levels of three samples of marketed green teas Sultan, Menara, Dahmis and an Earl Gray black tea reveal values higher than the recommended standards for children’s and adults. The fluoride level of the tea in the refreshment room is higher than that of the vending machine and family preparation tea. These results make it possible to warn the population facing the risk of developing dental fluorosis, by limiting the amount of fluorine ingested by the consumed food. Analyzes of fluoride levels of all types of tea products and tea preparation waters will provide measures to protect against excessive fluoride consumption.
Keywords: Fluorine, foods, teas, Morocco, excess, risk, fluorosis.
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Dibal, H. U., W. N. Dajilak, I. C. Lekmang, L. W. Nimze, and E. Y. Yenne. "Seasonal Variation in Fluoride Content in Groundwaters of Langtang Area, Northcentral Nigeria." Contemporary Trends in Geoscience 6, no. 1 (June 1, 2017): 11–27. http://dx.doi.org/10.1515/ctg-2017-0002.
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Abstract Thirty groundwater samples were collected at the peak of the rainy season and analysed for fluoride and other cations and anions in drinking water sources of Langtang area. For comparative purposes, thirty seven groundwater samples were collected in the dry season. The aim of the study was to determine variation in fluoride content with respect to the seasons. Fluoride in water was determined by the Ion Selective Electrode (ISE) and the cations by the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The anion (sulphate) was determined by Multi – Ion Colorimeter, bicarbonate and chloride by titration method. In addition fluorine content in aquifer materials from a borehole section were determined by Fusion method. The two seasons show variation in content of fluoride in groundwater. Fluoride content in groundwater is higher in the dry season ranging from 0.13 – 10.3 mg/l compared to the 0.06 – 4.60 mg/l values in the rainy season. Content of fluorine (0.01 wt %) in the aquifer materials (sands) is low from depth of 0 to 7.95 m. However, fluorine content increases with depth, from 7.95 to 10.60 m with concentration of 0.04 wt %, 0.05 wt % from 10.60 to 13.25m, and 0.07 wt % from 13.25 to 15.70 m, the content of fluorine however, decreased at depth 15.70 to18.55m with concentration of 0.02 wt % even with fluorite mineral in the aquifer material at this depth. Dilution of fluoride ion as a result of rain input which recharges the aquifer may be the main reason for lower values recorded in the rainy season. Over fifty and sixty percent of waters in both dry and rainy season have fluoride concentration above the WHO upper limit of 1.5 mg/l. Consumption of these elevated values of fluoride in groundwater of the study area, clearly manifests as symptoms of dental fluorosis.
3
Karpukhina, Natalia, Robert V. Law, and Robert G. Hill. "Solid State NMR Study of Calcium Fluoroaluminosilicate Glasses." Advanced Materials Research 39-40 (April 2008): 25–30. http://dx.doi.org/10.4028/www.scientific.net/amr.39-40.25.
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Fluorine containing calcium aluminosilicate glasses are widely used for a number of technological applications including dental cements, mould fluxes in steel making and in a variety of glass-ceramic systems. Despite of their importance these systems remain quite poorly understood with respect to their composition. To address this question a glass composition corresponding to the equimolar binary system anorthite−fluorite (Ca2Al2Si2O8−CaF2) was chosen as a base point for two series of compositions. One of the series is designed on the anorthite stoichiometry and considered as classically charge balanced. Another series starts from the fluorine free composition of the anorthite−lime (Ca2Al2Si2O8−CaO) stoichiometry and, therefore, is characterized by a disrupted network with at least one non-bridging oxygen (NBO) attached to silicon. A multinuclear 19F, 27Al, 29Si solid state NMR study of the glasses was undertaken. It is shown that in both series fluorine is predominantly coordinated by calcium, F−Ca(n), and in addition interacts with aluminium forming Al−F−Ca(n) complexes, where n denotes the number of first neighbouring calcium cations. Small amounts of high coordinated aluminium grows with increasing fluoride content in both glass series. However, the high coordinated aluminium may not be solely due to the formation of the Al−F−Ca(n) complexes. Glasses of the first series displayed systematic upfield shift of 29Si NMR resonance while substituting fluoride for oxide, starting from the fluorine free composition. This upfield shift is interpreted as the lack of cations in the network, due to formation of the F−Ca(n), which drives silicon network to polymerize toward a higher Qn structure. Contrary to the first series, the 29Si NMR resonance remains constant for fluorine containing compositions of the second series but differs downfield from the initial anorthite glass. The latter is explained by the excess of cations in the network due to addition of the fluorite resulting in formation of NBO on the silicon. Binding of fluorine with silicon is considered negligible in these systems. Thus, fluorine and calcium both define the degree of network polymerization and are considered as a cause for the changes in silicon and aluminium networks.
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Сорокин, Н. И., and Б. П. Соболев. "Собственная фтор-ионная проводимость кристаллических матриц фторидных супериоников: BaF-=SUB=-2-=/SUB=- (тип флюорита) и LaF-=SUB=-3-=/SUB=- (тип тисонита)." Физика твердого тела 61, no. 1 (2019): 53. http://dx.doi.org/10.21883/ftt.2019.01.46893.181.
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AbstractThe intrinsic fluorine-ion conductivity σ_lat of BaF_2 (CaF_2 fluorite type) and LaF_3 (tysonite type) crystals is studied by the impedance spectroscopy method. These compounds represent two major structural types taken as the basis to form the best nonstoichiometric fluorine-conducting solid electrolytes. The conductivity σ_lat caused by thermally activated defects is manifested in the field of high temperatures, where conductometric measurements are complicated by pyrohydrolysis. The experiments carried out in inert atmosphere with application of the impedance method have for the first time produced the reliable values of σ_lat of fluoride crystals in conditions of suppression of pyrohydrolysis (BaF_2) or partial pyrohydrolysis (LaF_3). Values of the σ_lat at 773 K for BaF_2 and LaF_3 crystals grown from melt by the Bridgman method using the vacuum technology are 2.2 × 10^–5 and 8.5 × 10^–3 S/cm differing by a factor of ~400. The tysonite structural type has been proved feasible for making high-conductivity solid fluoride electrolytes based on the analysis of energy characteristics of formation and migration of anionic defects.
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CHEN, Shi Yi, and Shou Ting Zhang. "Research on the Utilization and Industry Development Strategies of Fluorite Resources in China's Fluorine Chemical Industry." Advanced Materials Research 581-582 (October 2012): 142–45. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.142.
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This paper introduced fluorite resource profiles on the basis of elaborated China fluorite resource utilization status, focusing on analysis of fluorite in the fluorine chemical industry, discusses the problems of our country in the fluorine chemical industry development and firefly stone rational use of resources and the sustainable development of China's fluorine chemical industry recommendations.
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Fedorchuk, Yu M., V. V. Matvienko, D. V. Naryzhny, and A. S. Rybin. "Resource- and Energy-Saving Method for Obtaining Hydrogen Fluoride and Hydrite Fluoride." Voprosy sovremennoj nauki i praktiki. Universitet imeni V.I. Vernadskogo, no. 3(77) (2020): 032–39. http://dx.doi.org/10.17277/voprosy.2020.03.pp.032-039.
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An ecologically and economically effective technical solution has been developed for the production of hydrogen fluoride and fluorine hydrite by using fluorosulfonic acid in the decomposition technology of fluorspar. The stages of the technology of obtaining hydrogen fluoride and fluorine hydrite are shown: obtaining fluorosulfonic acid itself, decomposition of calcium fluoride with fluorosulfonic acid and hydrolysis of calcium fluorosulfonate with water vapor to form fluorosulfonic acid, recycled, hydrogen fluoride and fluorine hydrite. Experimental data have shown the promise of this technology.
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Liu, Hanyong, Qiao Zhu, and Xiaozhi Yang. "Electrical Conductivity of Fluorite and Fluorine Conduction." Minerals 9, no. 2 (January 27, 2019): 72. http://dx.doi.org/10.3390/min9020072.
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Fluorine is a species commonly present in many minerals in the Earth’s interior, with a concentration ranging from a few ppm to more than 10 wt. %. Recent experimental studies on fluorine-bearing silicate minerals have proposed that fluorine might be an important charge carrier for electrical conduction of Earth materials at elevated conditions, but the results are somewhat ambiguous. In this investigation, the electrical conductivity of gem-quality natural single crystal fluorite, a simple bi-elemental (Ca and F) mineral, has been determined at 1 GPa and 200–650 °C in two replication runs, by a Solartron-1260 Impedance/Gain Phase analyzer in an end-loaded piston-cylinder apparatus. The sample composition remained unchanged after the runs. The conductivity data are reproducible between different runs and between heating-cooling cycles of each run. The conductivity (σ) increases with increasing temperature, and can be described by the Arrhenius law, σ = 10^(5.34 ± 0.07)·exp[−(130 ± 1, kJ/mol)/(RT)], where R is the gas constant and T is the temperature. According to the equation, the conductivity reaches ~0.01 S/m at 650 °C. This elevated conductivity is strong evidence that fluorine is important in charge transport. The simple construction of this mineral indicates that the electrical conduction is dominated by fluoride (F−). Therefore, fluorine is potentially an important charge carrier in influencing the electrical property of Fluorine-bearing Earth materials.
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SCHUPPLI, P. A. "TOTAL FLUORINE IN CSSC REFERENCE SOIL SAMPLES." Canadian Journal of Soil Science 65, no. 3 (August 1, 1985): 605–7. http://dx.doi.org/10.4141/cjss85-065.
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Total fluorine was measured in a variety of Canadian soils using the lithium metaborate-nitric acid solution technique in conjunction with the fluoride electrode. Total fluorine ranged from 90 to 1000 mg∙kg−1. Key words: Soil fluorine analysis, fluoride electrode, CSSC reference soil samples
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Shevelev, G. A., L. I. Vasilenko, O. M. Pakhorukova, O. N. Kosheleva, T. S. Turmagambetov, E. N. Kamenskaya, N. G. Kamensky, and A. A. Dzyuba. "Emission determination of fluorine using «Grand-Potok» complex with sample injection into dc arc by spill-injection method." Industrial laboratory. Diagnostics of materials 85, no. 1II) (February 15, 2019): 45–49. http://dx.doi.org/10.26896/1028-6861-2019-85-1-ii-45-49.
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An additional photodetector array BLPP-369 was installed on a «Grand-Potok» complex for rapid atomic-emission determination of the fluorine concentration in fluorite samples. Introduction of fluorite samples was carried out using the spill-injection method simultaneously with high pure calcium oxide introduction using the second conveyor belt. The use of an additional photodetector array with a spectral range of 528 – 536 nm provides the possibility of expanding the spectrum of CaF molecular lines with the intensity sufficient for determination of fluorine concentrations in fluorite samples. A calibration curve for fluorine determination in a concentration range of 0.12 – 47.63% was plotted using measurement results for 200 fluorite samples. Integration of the additional photodetector array provided increased detection limit for the mass fractions of fluorine up to the maximum possible concentrations in fluorite samples. The observed effect simplifies and speeds up the analysis in the absence of the necessity to dilute the sample, thus reducing the error of measurements. The results show that there is no need to introduce additional buffer mixtures (except CaO) and use reference lines to determine the fluorine concentration, which also simplifies the measurement procedure.
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Komatsu, Hisanori, Katsushi Okuyama, Hiroko Yamamoto, Keisuke Yasuda, Masaharu Nomachi, and Yorihito Sugaya. "Tooth-bound fluoride uptake from fluoride-containing dental materials." International Journal of PIXE 23, no. 03n04 (January 2013): 127–34. http://dx.doi.org/10.1142/s0129083513410052.
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Whether fluorine penetrated from material completely incorporates into tooth mineral is a matter of debate, although it is well known that the fluoride from material penetrates directly into tooth structures. The purpose of this study is to determine tooth-bound fluoride uptake from fluoride-containing materials using PIGE/PIXE system at the Wakasa Wan Energy Research Center. Class V cavities in buccal surfaces of eighteen extracted human teeth were drilled and filled with six fluoride-containing materials. After being stored in distilled water for one year, a longitudinal section including materials was obtained from each tooth. Fluorine and calcium distribution of specimens were evaluated using PIGE/PIXE system. After evaluation, the specimens were immersed in 10 mL of 1M KOH solution and were agitated at room temperature for 24 h to remove a KOH soluble fluoride. The specimens were washed with 200 mL distilled water and left to dry. Again, to estimate tooth-bound fluorine (KOH-insoluble fluoride) uptake, the same portion of the specimens after KOH treatment were evaluated using PIGE/PIXE system. It was confirmed that fluorine penetrated from material partly incorporated into tooth mineral. This tooth-bound fluoride have the potential to prevent dental caries after loss of the bond between the filling material and tooth structure.
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Wang, Yi Ci, Jian Liang Zhang, Jing Wang, Fang Zhang, and Guo Ping Luo. "Gaseous Fluorides Formation Mechanism in the Roasting Process of the Fluorite-Bearing Iron Concentrate." Advanced Materials Research 690-693 (May 2013): 3498–505. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.3498.
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The gaseous fluorides formation mechanism in the roasting process of the fluorite-bearing iron concentrate was studied by thermodynamic calculation, differential thermal analysis (DTA) and chemical analysis. The results show that fluorine in the fluorite-bearing iron concentrate begins to escape since 400~500°C, and the emission rate of fluorine significantly increases when the temperature is above 1100°C; in the roasting process of fluorite-bearing iron concentrate, SiO2, K2O, Na2O, MgO, Al2O3 in the gangue and water vapor in roasting atmospher react with CaF2 in fluorite to generate such gaseous fluorides as SiF4, KF, NaF, MgF2, AlF3 and HF; with the increase of roasting temperature, the emission rate of fluorine increases obviously; and the water vapor in roasting atmosphere can improve escaping of fluorine.The results provide a theoretical basis for the improvement of roasting technology to reduce fluorine emission in the roasting or sintering process of Baiyanobo iron concentrate.
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Komuro, Matahiro, Yuichi Satsu, and Hiroyuki Suzuki. "Microstructure and Magnetic Properties of NdFeB Magnets Using Fluorides Nano-Coated Process." Materials Science Forum 638-642 (January 2010): 1357–61. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.1357.
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Nd2Fe14B magnets could be sintered using terbium fluoride coated Nd2Fe14B powders. Fluorine atoms were segregated at the triple junctions and grain boundary after sintering and aging process. NdOF with fcc structure was grown at the triple junction. Terbium atoms were also distributed near grain boundaries by interdiffusion between the fluoride and Nd2Fe14B. No fluorine atoms were detected in Nd2Fe14B phase. The coercivity for 0.5wt% terbium fluoride coated magnet showed 1.23 MA/m which was 1.2 times higher than that for non-coated magnet with 1.04MA/m. The distribution of terbium and fluorine atoms increases the coercivity without reduction of remanence.
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Grzechnik, Andrzej, and Karen Friese. "Fluorides containing lanthanides and yttrium at extreme conditions." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C55. http://dx.doi.org/10.1107/s2053273314099446.
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We are interested in crystal structures and stabilities of fluoride materials containing lanthanides and yttrium that are related to the CaF2 structure. These compounds are laser hosts and luminescent materials, oxygen sensors as well as components of solar cells. They exhibit various schemes of (dis)ordering of cations and anions in fluorite superstructures and anion-excess fluorites. In the last few years, we have performed a series of studies on the bulk AMF4 and MF3 materials (A = Li, Na, K; M = Y, lanthanide) at different pressure-temperature conditions. Among them, ordered LiYF4 is a commercial host for solid state lasers, while partially ordered NaYF4 doped with lanthanides is the most efficient material for green and blue up-conversion known to date. In the system KF–YF3, we have studied not only KYF4 [1] but also KY3F10, which is an anion-excess 2×2×2 superstructure of fluorite at atmospheric conditions. At high temperatures and high pressures, it converts to another fluorite superstructure with disordered fluorine atoms. The pressure-induced LaF3 post-tysonite structure is another example of the anion-excess fluorite [2]. Our work on the fluorite-related materials at extreme conditions provides information on their structural instabilities that could further be used to better understand and control their materials properties. For instance, we demonstrated that the NaMF4 up-converters are unstable and that the ordering of the cations and vacancies in their structure is a slow process [3]. Consequently, the order–disorder transformations have a profound influence over the luminescent properties of these materials when doped.
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Lyaruu, D. M., W. J. Lenglet, J. H. Wöltgens, and A. L. Bronckers. "Micro-PIGE determination of fluorine distribution in developing hamster tooth germs." Journal of Histochemistry & Cytochemistry 37, no. 5 (May 1989): 581–87. http://dx.doi.org/10.1177/37.5.2703697.
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A micro-PIGE (Proton-Induced gamma-ray Emission) technique based on the delayed 5/2+----1/2+ nuclear transition of fluorine (E gamma = 197 keV, t1/2 = 87 ns) emitted after 19F(p,p', gamma)19F reaction was used to detect and study the distribution of fluorine in the developing enamel organ during pre-eruptive stages, i.e., the transitional to early maturation stages of enamel formation in neonatal hamsters administered a single IP dose of sodium fluoride (20 mg NaF/kg body weight). The aforementioned nuclear reaction is unique for fluorine, and therefore detection of gamma-rays emanating from this reaction in a biological specimen implies a positive identification of fluorine at that particular site. Calcium and phosphorus X-rays were also recorded and used as parameters for assessment of the relationship between the degree of mineralization and fluoride incorporation into the enamel organ. The highest fluorine concentration in the enamel organ was recorded in the dentin near the dentin-enamel junction (DEJ). In the enamel, the highest concentration of fluorine was found to be associated with the more mature areas of the enamel near the DEJ, but gradually decreased in the direction of the enamel surface. Fluorine was not detected in the control germs. These results suggest that administration of fluoride in high doses during the pre-eruptive stages of enamel formation leads to incorporation of the ion into the forming dentin and enamel mineral, and that the enamel matrix does not seem to bind fluoride avidly.
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Chen, Rui Yang, Zhan Shi, Zhen Bin Zhang, and Miao Liu. "Study on the Defluorinated Materials of High Fluoride." Advanced Materials Research 535-537 (June 2012): 2195–200. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.2195.
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In our country, high fluoride containing groundwater is general. Now,there have been some study on fluoride containing groundwater, but MgSO4 is the first use. In this paper,therefore,study a new method for removing fluorine from groundwater with MgSO4 , CaO powder regulate pH, studies the influencing factors of fluorine removal rate, such as pH,temperature and so on, obtain the proper treatment condition:8% MgSO4 solution 10ml, CaO powder regulate pH11,stir 5min at 40°C. Using this method, the concentration of fluorine ion in the groundwater is lower than the national provided drinking water criterion of <1.0mg/L, fluorine removal rate reach 93%.
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Ding, Man Tang. "Research of Fluoride-Free Protective Slag Used in Low C Steel." Advanced Materials Research 803 (September 2013): 312–16. http://dx.doi.org/10.4028/www.scientific.net/amr.803.312.
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In order to eliminate the hazards of fluoride, the low melting point and boosting substances of Li2O, BaO, B2O3were added into the low C peritectic steel mold powder replaced fluoride. It makes fluorine-free protection slag successfully developed. The crystalline ore phase of Fluorine-free mould slag is melilite. By adjustment crystallization ratio of melilite in slag film, the heat flow through the mold can be controlled.
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Jian, Fang Fang, E. Liu, and Jun Ying Ma. "Interesting fluorine anion water clusters [F−·(H2O)n] in metal complex crystals." CrystEngComm 20, no. 27 (2018): 3849–57. http://dx.doi.org/10.1039/c8ce00532j.
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Three crystalline complexes containing fluorine anion water cluster were reported. The fluoride anions and water molecules are H-bonded to each other in an alternating fashion within the fluoride–water hybrid cluster, where a fluoride anion plays the important role.
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Zhukova, Anna G., L. G. Gorokhova, A. V. Kiseleva, T. G. Sazontova, and N. N. Mikhailova. "EXPERIMENTAL STUDY OF THE IMPACT OF LOW FLUORINE CONCENTRATIONS ON THE TISSUE LEVEL OF HSP FAMILY PROTEINS." Hygiene and sanitation 97, no. 7 (July 15, 2018): 604–8. http://dx.doi.org/10.18821/0016-9900-2018-97-7-604-608.
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Introduction. Fluoride in high concentrations has a toxic effect not only on bone tissue but also on the heart, liver, kidneys, and brain. In the implementation of the response to toxic doses of fluorine the proteins of the HSP family are involved regulating intracellular and tissue homeostasis under various stress effects. The toxic effect of high fluorine concentrations the mechanisms of which are disclosed in fluorosis can be realized and at a level significantly lower than a toxic one. In the literature, there is little data on the peculiarities of the effects of low fluorine concentrations at the tissue and cellular levels. The aim of the study. To investigate the impact of low fluorine concentrations on the tissue level of HSP family proteins in the brain and liver of laboratory animals. Material and methods. The experiments were carried out on 60 white male rats of the same age weighing 200-250 g. The rats were divided into 2 groups: the control and the group of the animals exposed to sodium fluoride (NaF) within 6 weeks (at a concentration of 10 mg/l corresponding to the daily fluorine dose of 1.2 mg/kg per body weight). We determined the level of inducible HSP72 and HSP32 (heme-oxygenase-1) referred to proteins of HSP family (Heat shock proteins), the activity of free radical processes and antioxidant enzymes (superoxide dismutase (SOD) and catalase) in the brain and liver tissues. Results. The important role of stress-inducible HSP72 protein in protecting the brain from the damage caused by the prolonged exposure to low fluorine concentrations was shown. In the liver, a protective role against fluoride exposure is played by the protein HSP32 with antioxidant properties. At the tissue level, the prolongation of the terms of the development of chronic fluoride intoxication with low fluorine concentrations was revealed. In the liver appeared to be the highly sensitive organ to the fluorine accumulation, the significant lesion was detected.
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Baheiraei, Nafiseh, and Mahmoud Azami. "Investigation of Fluorine Incorporation within Gelatin/Calcium Phosphate Nanocomposite Scaffold Prepared through a Diffusion Method." Advanced Composites Letters 22, no. 5 (September 2013): 096369351302200. http://dx.doi.org/10.1177/096369351302200503.
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In this study diffusional method was used to prepare a biomimetic calcium phosphate/gelatin nanocomposite as a scaffold for bone and tooth tissue engineering. Incorporation of fluorine into mineral phase of the scaffold was also investigated. Addition of fluoride to the synthesis process caused formation of fluoroapatite and calcium fluoride along with hydroxyapatite within gelatin while in the sample lacking fluorine atoms, hydroxyapatite and octacalcium phosphate were detected. With addition of fluorine within the structure of precipitated minerals, morphology of minerals was dramatically changed from oriented rod-like minerals with rectangular cross section toward spherical particles consisting of smaller crystals with uneven surface scattered over the gelatinous bulk material.
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Калугина (Kalugina), Ольга (Ol'ga) Владимировна (Vladimirovna), Татьяна (Tat'yana) Алексеевна (Alekseevna) Михайлова (Mikhailova), and Ольга (Ol'ga) Владимировна (Vladimirovna) Шергина (Shergina). "USE HERBAL PLANTS (CHAMAENERION ANGUSTIFOLIUM AND TANACETUM VULGARE) FOR MONITORING OF TERRITORIES POLLUTED BY FLUORINE-CONTAINING EMISSIONS." chemistry of plant raw material, no. 1 (March 6, 2019): 309–16. http://dx.doi.org/10.14258/jcprm.2019014097.
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Specific features of fluoride accumulation by two species of herbaceous plants – Chamerion angustifolium (L.) Holub and Tanacetum vulgare L., were found at different distances from the aluminum smelter located in the Baikal region. The highest fluorine content was recorded at the distance of 3 km from the smelter: 433 mg / kg of dry weight in C. angustifolium, 306 mg / kg in T. vulgare. According to the level of accumulation of fluorine, the organs of C. angustifolium were arranged in the following order (as the concentration decreases): leaves> roots> stems ≥ flowers, for T. vulgare the another sequence was typical: roots> leaves> flowers ≥ stems. Calculation of the root barrier coefficient for different organs of C. angustifolium and T. vulgare indicates the existence of barrier mechanisms that prevent the entry of fluorine from the soil into the aerial part of plants. A feature of the accumulation of fluoride in the leaves of C. angustifolium is its active foliar absorption and barrier-free intake from the soil. It has been established that the rate of fluoride accumulation by the reproductive organs of both species is much lower than by the assimilation organs. The data obtained make it possible to recommend using C. angustifolium for monitoring air fluorine pollution, and T. vulgare – for soil fluorine pollution.
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Ma, Zhi Jun, Yue Xin Han, and Yi Min Zhu. "Research on Fuxin Plant Coal Ash as a Fluoride-Containing Wastewater and Mechanism of Fluoride Removal." Advanced Materials Research 92 (January 2010): 213–20. http://dx.doi.org/10.4028/www.scientific.net/amr.92.213.
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Aimed at the status in China there are still some people who drink the water with excessive concentration fluorine, what may seriously threat to human health. For example Fuxin is an important production base in Liaoning province, which products aromatic compounds of fluorine. We found that the wastewater had large fluorine ion by testing the wastewater from the plant. It was polluted XiHe River and harmed to people’s health. So we chose the fly ash of Fuxin Plant as the agent to eliminate fluoride，then studied the mechanism of fluorine-removal and the physical properties of fly ash. Eventually we adopted the activation methods and combined the dynamic experiment and static experiment to research the mechanism to eliminate the fluorine with fly ash. The results of the experiment showed that the technology route was feasible which used the modified fly ash to get rid of the fluoride in the wastewater and reached the national emission standards.
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Wang, Li, Ye Zhang, Ning Sun, Wei Sun, Yuehua Hu, and Honghu Tang. "Precipitation Methods Using Calcium-Containing Ores for Fluoride Removal in Wastewater." Minerals 9, no. 9 (August 24, 2019): 511. http://dx.doi.org/10.3390/min9090511.
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F-containing wastewater does great harm to human health and the ecological environment and thus needs to be treated efficiently. In this paper, the new calcium-containing precipitant calcite and aided precipitant fluorite were adopted to purify F-containing wastewater. Relevant reaction conditions, such as reaction time, oscillation rate, dosage of hydrochloric acid, calcite dosage and the assisting sedimentation performance of fluorite, and action mechanism are analyzed. The experiment showed that the removal rate of fluoride in simulated wastewater reached 96.20%, when the reaction time, the dosage of calcite, the dosage of 5% dilute hydrochloric acid, and the oscillation rate was 30 min, 2 g/L, 21.76 g/L, and 160 r/min, respectively. Moreover, the removal rate of fluoride in the actual F-containing smelting wastewater reaches approximately 95% under the optimum condition of calcite dosage of 12 g/L, reaction time of 30 min, and oscillation rate of 160 r/min. The addition of fluorite significantly improves the sedimentation performance of the reactive precipitates. The experimental results showed that calcite and fluorite can effectively reduce the concentration of fluoride ions in F-containing wastewater and solve the problem of slow sedimentation of reactive precipitates.
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Liu, Jinhui, Xinfeng Wang, Weidong Xu, Mian Song, Lei Gong, Mengnan Zhang, Linbo Li, and Lishan He. "Hydrogeochemistry of Fluorine in Groundwater in Humid Mountainous Areas: A Case Study at Xingguo County, Southern China." Journal of Chemistry 2021 (July 14, 2021): 1–11. http://dx.doi.org/10.1155/2021/5567353.
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The understanding of F− concentration in groundwater in humid areas is limited although there are lots of research on high-fluoride groundwater in arid areas. In this paper, with controlling factors of F− concentrations in humid areas as the focus, 130 groundwater samples, obtained from four subsystems in Northwest Xingguo County, Jiangxi Province, China, were investigated to demonstrate the controlling factors of F− concentrations in humid areas. According to analytical results, the following hydrogeochemical characteristics of the fluorine in humid mountainous areas were determined: (1) F− concentration is positively correlated with total dissolved solids (TDS), Ca2+, HCO 3 − , and pH; (2) the groundwater features a high flow rate and low TDS; (3) the equilibrium constant of CaF2 is less than its solubility product constant, and the fluorine-bearing minerals in rocks are in a dissolved state; and (4) the dissolved fluoride-bearing minerals constitute the main sources of F− in the groundwater. Fluorine mainly comes from groundwater fluorine-bearing minerals in metamorphic rocks. Moreover, the low F− concentration in the groundwater mainly results from the fast flow rate of groundwater. Fluoride in groundwater has great potential hazards in humid areas.
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Apostolovic, Mirjana, Biljana Kalicanin, Marija Igic, Olivera Trickovic-Janjic, Dusan Surdilovic, Ljiljana Kostadinovic, Branislava Stojkovic, and Dragan Velimirovic. "Migration of fluoride ions from the permanent teeth into saliva in children with glass ionomer cement restorations: An in vitro study." Vojnosanitetski pregled 70, no. 3 (2013): 279–83. http://dx.doi.org/10.2298/vsp1303279a.
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Bacground/Aim. Glass ionomer cements (GIC) belong to the group of polycarboxyl cements, and one of the principal characteristics of these materials is their anticariogenic potential of fluorine release into saliva and enamel-dentin substance. The aim of this study was to examine the content of released fluorine from GIC restorations (Fuji IX, GC, Japan) of young permanent teeth in the medium of artificial saliva and similar releases in the same medium by the restorations of these teeth treated with a low concentration fluoride solution. Methods. We examined 12 premolars exctracted from orthodontic reasons. The GIC restored teeth were divided into the group treated daily with low concentration fluoride solution (334 ppm) and the control, not treated group. The samples of artificial saliva were analyzed for fluorine ion content using an ion selective electrode. Results. Our comparative analysis of the mean values using the Student?s t-test demonstrated a statistically significant difference in fluorine ion concentration in artificial saliva of fluoridated and non-fluoridated teeth with GIC fillings after 14 and 21 days (p < 0.05), while the difference detected after 7 days was with no statistical significance. Conclusion. The results of this in vitro study indicated that low-concentration fluoride solutions could serve to refluoridate GIC fillings and contribute to an increased fluorine content in saliva. The process of refluoridation of GIC fillings should be advised 2-3 weeks after the restoration, since the release of fluorine from GIC fillings diminishes in time.
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Okuyama, K., Y. Tamaki, H. Yamamoto, K. Yagi, M. Hayashi, Y. Matsuda, T. Saito, K. Yasuda, K. Suzuki, and H. Sano. "Fluorine binding with dentin adjacent to fluoride-containing luting materials." International Journal of PIXE 27, no. 01n02 (January 2017): 1–9. http://dx.doi.org/10.1142/s0129083518500018.
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Tooth-bound (KOH-insoluble) fluoride contributes to caries prevention because of its low acid solubility and long retention within tooth structure. The purpose of this study was to evaluate tooth-bound fluoride in dentin, taken up from fluoride-containing luting materials, using an in-air [Formula: see text]PIXE/PIGE system. The dentin surface of tooth root cross-sections and an acrylic resin were cemented with four different fluoride-containing luting materials. Specimens were stored in a remineralizing solution for 4 or 8 weeks and then sectioned into two slices. Two adjacent slices were used for measurement of fluorine and calcium concentration using in-air [Formula: see text]PIXE/PIGE. For analysis of the KOH-insoluble fluoride ((KOH(+)), one slice was immersed in 1 mol/L KOH solution for 24 h. The other slice was not treated with KOH in order to analyze KOH-soluble and -insoluble fluoride (whole fluoride, KOH(−)). KOH(+) levels were lower than KOH(−) levels for all materials at both duration periods. Higher concentration of fluorine was detected at deeper areas in the 8-week groups than in the 4-week groups for all materials. The material, which has the largest fluoride release, shows the lowest ratio of KOH(+) to KOH(−). PIXE/PIGE analysis confirmed the presence of tooth-bound fluoride in dentin adjacent to fluoride-containing luting materials.
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Ophaug, R. "Determination of Fluorine in Biological Materials: Reaction Paper." Advances in Dental Research 8, no. 1 (June 1994): 87–91. http://dx.doi.org/10.1177/08959374940080011501.
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Although the fluorine in human tissues may exist in both inorganic and organic (covalently bound) forms, the inorganic fraction is clearly the most relevant for assessing human exposure to, and utilization of, environmental fluoride. There is now general agreement that the inorganic fraction of total tissue fluorine can be accurately determined by a variety of analytical techniques. One of the basic questions considered at this workshop is whether the analysis of a specific tissue or body fluid can provide an estimate of how much of the fluoride to which an individual is exposed actually enters and accumulates in the body. The analysis of hair and nails has been used as an indicator of exposure and utilization for several trace elements, including fluoride. Due to methodological uncertainties regarding sampling and pre-analysis treatment, however, it is presently not possible clearly to distinguish fluoride which is incorporated into hair and nails during formation (endogenous) from that which becomes associated with the tissues following exposure to the environment (exogenous). Consequently, although the fluoride content of hair and nails is clearly increased by environmental exposure to fluoride, the conclusion that these tissues are suitable indicators of fluoride utilization and accumulation in the body is premature.
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Peckham, Stephen, and Niyi Awofeso. "Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention." Scientific World Journal 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/293019.
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Fluorine is the world’s 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed.
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Koç, Evren, and Başaran Karademir. "Tendürek Sönmüş Yanardağının Florotoksik Kaynak Suları Örneğinde Doğal Florozisin Çiftlik Hayvanı Kemiklerinin Flor Düzeyleri Üzerine Etkisi." Turkish Journal of Agriculture - Food Science and Technology 9, no. 2 (February 23, 2021): 333–38. http://dx.doi.org/10.24925/turjaf.v9i2.333-338.3936.
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It is known that the level of Fluoride in the spring waters from some volcanic lands is high and these waters cause Fluoride toxicity. Scientific studies have shown that in Doğubayazıt there is high amount of fluoride in some spring waters originating from the foothills of Tendürek volcano and normal level in Iğdır and Cappadocia volcanic lands. In this study, it was revealed comparatively how the spring waters in these regions affect the bone Fluoride levels of farm animals that are given as drinking water. Fluoride analyses in bone, water and urine samples were performed by means of an ion meter equipped with an iron selective electrode (ISE). The urine and bone fluoride levels of farm animals followed a similar course to water samples. Fluoride levels in bone and urine samples of Doğubayazıt were detected to be significantly higher in compared to Igdır and Cappadocia regions. Bone Fluoride analysis results were also supported by external bone and dental examination findings. The presence of a strong relationship between the analysed water, urine and bone Fluoride levels was determined in this study. It was found that drinking water has a very strong effect on urine and bone in terms of fluoride level. Consequently, Fluorine levels in the bones of farm animals drinking water with high Fluorine levels originating from Tendürek Mountain in Doğubayazıt were found to be higher than normal. Fluoride levels in the bones of farm animals that drank high-fluoride waters originating from Tendurek mountain in Doğubayazıt were found to be higher than normal. This situation can be evaluated as evidence that natural Fluoride toxicity formed by drinking water causes Fluoride accumulation on bones.
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Iram, Arshi, and Soumanna Datta. "CORRELATION BETWEEN FLUORINE CONTAMINATED ANIMAL FODDER AND CATTLE MILK IN HIGH RISK FLUOROSIS DISTRICTS OF RAJASTHAN." International Journal of Advanced Research 9, no. 03 (March 31, 2021): 25–29. http://dx.doi.org/10.21474/ijar01/12549.
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The toxic effects of fluorine depend on the intake into the body, the solubility and bio-availability of it. When daily intake of fluorine is 0.5 to 1.7 mg/kg body wt. in the form of sodium fluoride produces dental lesions in growing animals without affecting general health, whereas the adult animals can tolerate double the dose of the above intake i.e. 1 to 3.5 mg/kg. body weight per day, Minor teeth lesion occurs at 5 ppm. In cattle lateral incisors show most pronoused changes. Mottling of tooth enamel, erosion of teeth are the earlier signs of dental fluorosis. Lucerne, Barley, Common Duckweed, Rapeseed, Red Clover, False oat grass, Rye grass, Corn, Millet, Sorghum, Wheat were analyzed in all seven districts, fluoride ranges from 2.197±0.107 to 5.624±0.219mg/kg in Lucerene and False oat grass respectively. Buffalos milk (6.034±1.837ppm) of Nagore district was highly contaminated.As concentration of fluoride increase in drinking water, there was increased concentration of fluoride in milk, blood and urine.
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Tian, Kun Viviana, Gregory A. Chass, and Devis Di Tommaso. "Simulations reveal the role of composition into the atomic-level flexibility of bioactive glass cements." Physical Chemistry Chemical Physics 18, no. 2 (2016): 837–45. http://dx.doi.org/10.1039/c5cp05650k.
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Azua Jamari, Nor Laili, Arne Behrens, Andrea Raab, Eva M. Krupp, and Jörg Feldmann. "Plasma processes to detect fluorine with ICPMS/MS as [M–F]+: an argument for building a negative mode ICPMS/MS." Journal of Analytical Atomic Spectrometry 33, no. 8 (2018): 1304–9. http://dx.doi.org/10.1039/c8ja00050f.
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The paper describes that the 2nd ionisation potential and the difference in bond energy of a metal to fluorine bond and of a metal to oxygen bond are the most important parameters to form a metal fluoride ion for the detection of fluorine in ICPMS/MS.
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Fu, Lingxia, Yanxia Yang, Longlong Zhang, Yuanzhi Wu, Jun Liang, and Baocheng Cao. "Preparation and Characterization of Fluoride-Incorporated Plasma Electrolytic Oxidation Coatings on the AZ31 Magnesium Alloy." Coatings 9, no. 12 (December 5, 2019): 826. http://dx.doi.org/10.3390/coatings9120826.
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In this study, films with different fluorine contents were prepared on an AZ31 magnesium alloy by using plasma electrolytic oxidation to study the corrosion resistance and cytocompatibility of the alloy. The morphology of the coating surface, phase, and chemical elements were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectrometry (EDS). The changes in the corrosion resistance with different fluorine contents were investigated by electrochemical experiments, hydrogen evolution, and long-term immersion tests. In addition, murine fibroblast L-929 cells were adopted for in vitro cytotoxicity tests using the cell counting kit (CCK)-8 assay, and the morphology of the cells was observed simultaneously by inverted microscopy. The results showed that the main form of the fluorine ions in the plasma electrolytic oxidation coatings was magnesium fluoride (MgF2). In addition, the corrosion resistance and cytocompatibilities of the coatings were improved by the addition of fluoride ions. When the content of potassium fluoride reached 10 g/L, the cell compatibility and corrosion resistance were the best, a finding which provides a basis for the clinical applications of the AZ31 magnesium alloy in the biomedical field.
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Trigub, Valentina. "Medical-geographical assessment of fluoride in natural components of Odessa region." Visnyk of the Lviv University. Series Geography, no. 41 (September 17, 2013): 358–66. http://dx.doi.org/10.30970/vgg.2013.41.2008.
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Geographic features of fluoride in groundwater and surface (including drinking) waters of the Odessa region and Odessa city are established. Found some correlation between dental diseases of population of Odessa region and contents of the fluoride in drinking waters. Key words: fluorine, natural ingredients, drinking waters, dental diseases, Odessa region, medicalgeographical assessment.
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Chaudhary, Praveen, Mario Bieringer, Paul Hazendonk, and Michael Gerken. "The structure of trimethyltin fluoride." Dalton Transactions 44, no. 45 (2015): 19651–58. http://dx.doi.org/10.1039/c5dt01994j.
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ATASOY, Ayse Dilek, Mehmet İrfan YEŞİLNACAR, Benan YAZICI, and Müge ÖZDEMİR ŞAHİN. "FLUORIDE IN GROUNDWATER AND ITS EFFECTS ON HUMAN HEALTH." World Journal of Environmental Research 6, no. 2 (April 15, 2017): 51. http://dx.doi.org/10.18844/wjer.v6i2.1324.
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Fluoride contents higher than the permissible levels lead to negative effects on the human health. More than 200 million people in the world were adversely affected from the fluoride. Fluoride levels in water were higher than the World Health Organization’s (WHO) recommended level. Endemic fluorosis originating from the consumption of high fluorine water was observed also in some parts of Anatolia. Volcanic formations are found in areas with high fluoride concentrations in ground waters. In this study, fluoride concentration of water was researched in Şanlıurfa where comprised generally sedimental formations and where the fluorosis cases were identified on the primary school students. High fluoride levels were assigned in water samples from the wells in Sarım and Karataş villages in Şanlıurfa. Keywords: Fluoride, hydrogeochemistry, dental fluorosis, Şanlıurfa
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Gao, Zong Jun, Xi Zhu, Yu Tian, Yang Min Ma, and Jia Jia Li. "The Relationship between High Fluorine Groundwater and Geological Environment in Gaomi." Advanced Materials Research 671-674 (March 2013): 156–60. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.156.
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Drinking fluoride water is the root cause of serious endemic fluorosis in Gaomi. According to the investigation and sampling test, this paper analysis the relationship between high fluoride water and stratigraphic units and topography: in stratigraphic, high fluoride areas, heituhu Formation and the Yihe Formation are consistent; in topography, high fluoride areas and flood plain landscape are matching. Thus we can summarize the conditions for the formation of high fluoride water. Depending on the analysis of the data, this paper points out the relationship between the fluorine and other elements in the water, especially the fluorine’s close relationship with Mg, Se, Sr. Countermeasures Measures and suggestions on fluoride removal are also provided.
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Zhang, Yongzhi, Li Chen, Yan Meng, Xiaopeng Li, Yong Guo, and Dan Xiao. "Sodium storage in fluorine-rich mesoporous carbon fabricated by low-temperature carbonization of polyvinylidene fluoride with a silica template." RSC Advances 6, no. 112 (2016): 110850–57. http://dx.doi.org/10.1039/c6ra24386j.
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Starikova, A. E., E. V. Sklyarov, and V. V. Sharygin. "Y-REE mineralization in biotite-arfvedsonite granites of the Katugin rare-metal deposit, Transbaikalia, Russia." Доклады Академии наук 487, no. 1 (July 19, 2019): 88–92. http://dx.doi.org/10.31857/s0869-5652487188-92.
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We provide the results of study of the extremely enriched in Y-REE carbonate-fluorine isolations from biotite-arfvedsonite granite of the Katugin rare metal deposit. New chemical data of isolations mineral phases - gagarinite-(Y), tveitite-(Y), fluocerite-(Ce), basnaesite, fluornatropyroclore, are delivered. Carbonate-fluoride globule in quartz of hosting granite gives possibility to estimate crystallization order. This finding might be the evidence of silicate-fluorine immiscibility suggested before for Y-REE segregations in the Katugin granites. Fluorine melt segregation took likely place at the magmatic stage of biotite-arfvedsonite granite formation. It causes host granite depletion with fluorine and redistribution of REE and Y in fluorine salt melt.
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Latif, Farzana, Abdul Malik, and Wolfgang Voelter. "Notizen: Epoxide Assisted Displacement of Triflyl Group by Fluoride Ion. An Efficient Approach to Fluorodeoxy Sugars." Zeitschrift für Naturforschung B 40, no. 2 (February 1, 1985): 317–18. http://dx.doi.org/10.1515/znb-1985-0229.
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Abstract Displacement of triflyl group by fluoride ion in benzyl 2,3-anhydro sugars leads with stereochemical inversion to fluorodeoxy sugars, providing a general method for the introduction of fluorine in the neighbourhood of oxirane ring in anhydro sugars. This procedure is mild, convenient, and does not experience difficulties which sometime are encountered in nucleophilic fluoride displacements in carbohydrate systems.
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Zhang, Chenhu, Jiande Gao, Yuehua Hu, Wei Sun, Fei Lv, and Zhenjun Liu. "Clean and Feasible Utilization of High Silica Fluorspar Powder via Reverse Flotation: A Pilot Study." Minerals 11, no. 6 (May 24, 2021): 555. http://dx.doi.org/10.3390/min11060555.
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Fluorite is a nonrenewable mineral used to produce anhydrous hydrofluoric acid (AHF) and aluminum fluoride. The demand for low-grade fluorite powder (CaF2 < 97%) has fallen sharply owing to the current market conditions. Therefore, a large number of fluorite concentrates have been improved by acid leaching. While this approach can efficiently remove CaCO3 from fluorite concentrate, the SiO2 content, which significantly affects AHF consumption during the production of HF or aluminum fluoride, cannot be completely removed. To solve this problem, in this study, we used reverse flotation before leaching the fluorite concentrates. Subsequently, the feasibility of reverse flotation desilication was determined. The obtained results of the ZP (zeta potential) measurements, solution chemistry analysis, FTIR (Fourier transform infrared spectroscopy) analysis, and micro-flotation tests indicated that employing dodecylamine as the collector and citric acid as the depressor could effectively separate sericite from fluorite. The batch flotation experiment and the pilot test were conducted in Chenzhou (Hunan, China) followed by their operation in Xinyuan Mining Co. Ltd., which produces monolithic fluorite ore on the large scale in Asia. Notably, we found that the contents of both SiO2 and Al2O3 were from 2.82%, 1.17% reduced to 1.28%, 0.74% in the batch flotation experiment. The results of the pilot test showed that the new reverse flotation + leaching technology could dramatically reduce the potential environmental impact and costs, thereby significantly improving the economic benefits by satisfying the requirements of the market.
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Nurmatova, N. T., V. R. Kayumova, D. U. Rakhmatullaeva, and F. Kh Khodzhaeva. "Scientific rationale for the use of dietary supplements based on Ganoderma luсidum in the comprehensive prevention of dental caries in children." Стоматология детского возраста и профилактика 20, no. 1 (April 1, 2020): 15–18. http://dx.doi.org/10.33925/1683-3031-2020-20-1-15-18.
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Relevance. Numerous studies on the etiology, diagnosis and treatment of decay of temporary teeth objectify the relevance of this problem. Currently used fluoride preparations are very effective, but nonetheless, there is an increase in caries from year to year. Therefore, as an addition to fluorine preparations, the use of dietary supplements based on Ganoderma Lucidum has been proposed. Purpose. Conduct an open, randomized study of the dietary supplements based on the Ganoderma Lucidum in the comprehensive prevention of dental caries in children. Materials and methods. To achieve this goal, 78 children aged 3 to 12 years were examined in terms of indicators: estimates of the prevalence of caries (%), the intensity of caries (CSD – carious, sealed, distant and CFS – carious, filled surfaces), the simplified OHI-S index (Green-Wermillion), CPITN, and oral cavity IG according to Kuzmina EM. (2000). All children, depending on the prevalence of caries, were divided into 2 groups: group 1 – the main (41 children, age 6.4 ± 4.8 years) – for complex prevention, fluoride preparations were used with dietary supplements based on Ganoderma Lucidum, group 2 – comparison group (37 children, age 7.3 ± 3.7 years) – fluorine preparations were used for complex prophylaxis. Results. After 4 months of application of the dietary supplements based on Ganoderma Lucidum, an improvement in oral hygiene was recorded. So, in the main group, IG improved by 57% and amounted to 0.21 ± 0.02, in the comparison group – by 33% and amounted to 0.52 ± 0.03 (p≤0.05). In the comparison group, before the use of fluoride preparations, the% of sanitized was 63%, whereas after the use of fluorine this indicator was 72%. The CSD index before application was 3.32 ± 0.01 and after application was 2.56 ± 0.02. CPITN before use was 1.2 ± 0.04 whereas after use it was 0.76 ± 0.03. OHI-S before application was 40.03% and after application of fluorine it was 21.05%. The increase in caries before the use of fluorine was 0.76 ± 0.04 and after the use of fluorine was 0.33 ± 0.02.Conclusions. The use of dietary supplements based on Ganoderma Lucidum in combination with fluorine preparations is more appropriate for a comprehensive prevention program than the usual use of fluorine preparations.
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Chungong, Louis Forto, Mark A. Isaacs, Alexander P. Morrell, Laura A. Swansbury, Alex C. Hannon, Adam F. Lee, Gavin Mountjoy, and Richard A. Martin. "Insight into the atomic scale structure of CaF2-CaO-SiO2 glasses using a combination of neutron diffraction, 29Si solid state NMR, high energy X-ray diffraction, FTIR, and XPS." Biomedical Glasses 5, no. 1 (January 1, 2019): 112–23. http://dx.doi.org/10.1515/bglass-2019-0010.
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Abstract Bioactive glasses are important for biomedical and dental applications. The controlled release of key ions, which elicit favourable biological responses, is known to be the first key step in the bioactivity of these materials. Properties such as bioactivity and solubility can be tailored for specific applications. The addition of fluoride ions is particularly interesting for dental applications as it promotes the formation of fluoro-apatite. To date there have been mixed reports in the literature on how fluorine is structurally incorporated into bioactive glasses. To optimize the design and subsequent bioactivity of these glasses, it is important to understand the connections between the glass composition, structure and relevant macroscopic properties such as apatite formation and glass degradation in aqueous media. Using neutron diffraction, high energy X-ray diffraction, 29Si NMR, FTIR and XPS we have investigated the atomic scale structure of mixed calcium oxide / calcium fluoride silicate based bioactive glasses. No evidence of direct Si-F bonding was observed, instead fluorine was found to bond directly to calcium resulting in mixed oxygen/fluoride polyhedra. It was therefore concluded that the addition of fluorine does not depolymerise the silicate network and that the widely used network connectivity models are valid in these oxyfluoride systems.
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LI, SHUOFU, DAOZHEN GONG, WEI ZHANG, GENZHUANG LI, and KOU JUE. "IMPROVING FLUORITE FLOTATION UNDER LOW TEMPERATURE AND NEUTRAL pH CONDITIONS." Surface Review and Letters 27, no. 08 (December 9, 2019): 1950187. http://dx.doi.org/10.1142/s0218625x19501877.
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The authors provide insight into the problem of selective flotation of fluorite from quartz–fluorite ores. The flotation of fluorite mineral from ores by using acidized water glass as depressant has been studied for substitution of the commonly used depressant. It was found that the acidized water glass could achieve higher selectivity of fluorite minerals against gangue minerals in the fluorite flotation. The experimental results showed that YF collector has high selectivity in the flotation of fluoride for low-grade fluorite ores. The use of the YF collector also made it unnecessary to heat the pulp to a high temperature and achieved an acceptable reduction in the flotation temperature to [Formula: see text]C. The YF collector should be used in neutral pH to separate fluorite from gangue and it could also improve fluorite recovery and flotation rate.
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Park, Seung Hyun, Kyung Eon Kim, and Sang Jeen Hong. "Surface Analysis of Chamber Coating Materials Exposed to CF4/O2 Plasma." Coatings 11, no. 1 (January 18, 2021): 105. http://dx.doi.org/10.3390/coatings11010105.
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Coating the inner surfaces of high-powered plasma processing equipment has become crucial for reducing maintenance costs, process drift, and contaminants. The conventionally preferred alumina (Al2O3) coating has been replaced with yttria (Y2O3) due to the long-standing endurance achieved by fluorine-based etching; however, the continuous increase in radio frequency (RF) power necessitates the use of alternative coating materials to reduce process shift in a series of high-powered semiconductor manufacturing environments. In this study, we investigated the fluorine-based etching resistance of atmospheric pressure-sprayed alumina, yttria, yttrium aluminum garnet (YAG), and yttrium oxyfluoride (YOF). The prepared ceramic-coated samples were directly exposed to silicon oxide etching, and the surfaces of the plasma-exposed samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. We found that an ideal coating material must demonstrate high plasma-induced structure distortion by the fluorine atom from the radical. For endurance to fluorine-based plasma exposure, the bonding structure with fluoride was shown to be more effective than oxide-based ceramics. Thus, fluoride-based ceramic materials can be promising candidates for chamber coating materials.
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Klačić, Tin, Marko Tomić, Danijel Namjesnik, Borna Pielić, and Tajana Begović. "Mechanism of surface reactions and dissolution of fluorite surface in an aqueous electrolyte solution." Environmental Chemistry 16, no. 7 (2019): 529. http://dx.doi.org/10.1071/en19013.
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Environmental contextSolubility and dissolution rates of mineral surfaces depend on both the surface properties of the mineral and the composition of the aqueous solution. We investigated the link between the interfacial reactions and dissolution of a fluorite crystal. The study provides a detailed microscopic picture of the dissolution phenomena at the fluorite surface, and the results have wider application to general mineral dissolution processes taking place in the environment. AbstractDissolutions of the fluorite (111) crystallographic plane and fluorite (CaF2) colloidal particles were studied as a function of pH. The process was examined by measuring the concentration of released fluoride and calcium ions by ion-selective electrodes. Additionally, electrokinetic and inner surface potentials were measured by means of electrophoresis and a fluorite single crystal electrode respectively. The rate of fluorite dissolution was analysed assuming a reaction mechanism with a series of elementary steps, which included the reaction of surface groups with H+ ions, the formation of F− vacancies, the dissociation of surface groups and the release of calcium and fluoride ions into the interfacial region as well as the diffusion of ions from the interfacial region. The proposed reaction mechanism indicates that H+ ions play a necessary role in allowing the dissolution to take place, a concept not possible to confirm by looking at the overall equation of fluorite dissolution. The order of the total reaction with respect to H+ ions was found to be 0.37, which is in good accordance with the value derived from the reaction mechanism (1/3). The experimentally determined rate coefficient of fluorite dissolution was found to be kdis=9×10−6mol2/3dmm−2s−1.
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Petlin, Ilya V., and Margarita S. Lesnikova. "WAYS OF PROCESSING AND RECYCLING OF FLUORINE-CONTAINING WASTE OF ALUMINUM INDUSTRY." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 4 (May 12, 2017): 108. http://dx.doi.org/10.6060/tcct.2017604.5352.
Full textAbstract:
The information on aluminum metal production volume, its application areas and ecological problems which go with aluminum production are described. The data on fluorine containing waste products types and quantity at aluminum production were reported. The aluminum production waste products negative influence on environment was identified. For hydrogen fluoride production the use of fluorine containing waste products as alternative man-made raw material is offered. Resource effective and resource saving method of aluminum production fluorine containing waste products processing is described in detail. Processing method consists waste oxidizing calcining to move away carbon component, interaction of sulfuric acid with fluorine containing particles to product hydrogen fluoride, dissolution of solid sulphatisation product and aluminum hydroxide precipitation. Aluminum oxide and sodium sulfate can be byproducts of describing wastes processing method. Aluminum oxide can be used for production run of aluminum metal electrolytic production. Sodium sulfate can be used in glass and cellulose production, in textile and tanning industries. The thermodynamic calculations of fluorine containing wastes components with sulfuric acid chemical interaction are given. The research of kinetics of fluorine containing wastes with sulfuric acid chemical interaction by method of reacting mixture unstoppable weighing with mass auto-registration have been carried out. The dependence of transformation (reaction) degree on the time in temperature range of 220 to 260 ºС has been identified. It was characterized by Krank-Gistling-Braunstein equation. On obtained dependence the reaction area and process rate-limiting step was determined. The methods of intensification of aluminum industry fluorine containing wastes interaction process in observed temperature range has been offered. The economic and ecologic effect of aluminum industry fluorine containing wastes processing method has been established.Forcitation:Petlin I.V., Lesnikova M.S. Ways of processing and recycling of fluorine-containing waste of aluminum industry. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 108-113.
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He, Xianghong, and Bing Yan. "Yttrium hydroxide fluoride based monodisperse mesocrystals: additive-free synthesis, enhanced fluorescence properties, and potential applications in temperature sensing." CrystEngComm 17, no. 3 (2015): 621–27. http://dx.doi.org/10.1039/c4ce01823k.
Full textAbstract:
Fluorine-containing monodisperse mesocrystals constructed by nanorods were synthesized via an additive-free hydrothermal route and Eu3+ was successfully incorporated into the yttrium hydroxide fluoride host lattice.
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Mystkowska, Joanna, Gabriel Rokicki, Jarosław Sidun, and Jan Ryszard Dąbrowski. "Mechanical and Physicochemical Properties of Some Originally Made Composite Materials for Dental Fillings." Solid State Phenomena 165 (June 2010): 142–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.165.142.
Full textAbstract:
This work presents results of research on compressive strength, microhardness, polymerization shrinkage and water sorption of some specially developed composite materials for dental fillings. The investigated powder fillers were divided into two groups: fluorine-based fillers, such as fluoridated glass, strontium fluoride, ytterbium fluoride and additives of improved mechanical characteristics such as nanosilica and polyethylene. The influence of fluoride ion source on the properties of the composite materials was evaluated. Tests were performed just after the material polymerization and, additionally, after seven, thirty and sixty days. Some small differences between composites were observed.
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Li, Sheng Tao, Wei Dong Shi, Yang Zhang, Sen Qi Zhang, and Xiao Gang Shang. "Study on Formation Mechanism of High-Fluoride Groundwater in Guide Basin." Advanced Materials Research 550-553 (July 2012): 2515–20. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.2515.
Full textAbstract:
As high-fluoride poisoning is widespread in Guide Basin, formation mechanism study is of significance for local water quality improvement. Through analysis of regional geology, tectonics and petrography, the provenances are confirmed that metamorphic rocks from Archean to Lower Proterozoic periods are the original provenance of fluorine and the Miocene - Pliocene Guide Group stratum of fine lake sediments, which is rich in organic matter, is the secondary provenance. Moreover, confined groundwater occurring in the Guide Group stratum, which has a fluoride content of 0.32~4.57mg/L, is the main groundwater of high fluoride in the study area. The distribution of confined groundwater obviously controlled by the compression-tortion fault with NNW striking and tension-shear fault with NEE striking forms two abnormal centers. The anomaly area spreads around the NEE shear and forms an ellipse shape, which has a north-south width of 5km and a east-west length of approximately 10km. In further study, the distribution characteristics of high-fluoride groundwater in the plane is discovered generally to be consistent with the distribution of groundwater, and has a positive correlation with depth and temperature of boreholes. This phenomenon indicates that the high-fluoride groundwater is likely controlled by the geothermal anomaly, and the geological effects of thermal dynamics may play an important role in the control of fluorine in enrichment, migration and transformation.
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Alonso, Pedro, Pilar Pardo, Francisco J. Fañanás, and Félix Rodríguez. "A fast, efficient and simple method for the synthesis of cyclic alkenyl fluorides by a fluorinative carbocyclization reaction." Chem. Commun. 50, no. 92 (2014): 14364–66. http://dx.doi.org/10.1039/c4cc07376b.
Full textAbstract:
Tetrafluoroboric acid promotes a fluorinative carbocyclization reaction to give cyclic alkenyl fluorides in a process where the incorporation of the fluorine atom occurs through the nucleophilic addition of a fluoride anion.